Method for forming an integrated mass

ABSTRACT

METHOD FOR FORMING FILBROUS MATS OR INTERGRATED FIBROUS MASSES FOR A COLLECTION OF LINEAR BODIES BY PROVIDING A PLURALITY OF MAT-LIKE LAYERS WHICH MAY RESULT FROM THE DEPOSITION OF LINEAR BODIES ON A COLLECTING SURFACE, INTERLEAFING BINDER IN FILM FORM BETWEEN THELAYERS, AND ACTIVATING THE FILM TO DISPERSE THE BINDER AMONG THE INDIVIDUAL BODIES TO BIND THEM INTO AN INTERGRATED FIBROUS MASS, SUCH AS AIR FILTER MATS, INSLUATING MATS, OR THE LIKE.

1, 1972 G. E. SMOCK 3,681,157

METHOD FOR FORMING AN INTEGRATED MASS Original Fil ed Dec. 29, 1965 jTEMPERATURE- CONTROL 6? 50 INVENTOR; 5 6204 65 4. fi/r/aq/i 7 BY IATTORNEYS v United States Patent O 3,681,157 METHOD FOR FORMING ANINTEGRATED MASS George E. Smock, Newark, Ohio, assignor to Owens-Corning Fiherglas Corporation Continuation of application Ser. No.785,045, Dec. 12, 1968, which is a continuation of application Ser. No.517,225, Dec. 29, 1965. This application Mar. 12, 1970,

Ser. No. 18,372

Int. Cl. B32b 17/00 US. Cl. 156-62.2 4 Claims ABSTRACT OF THE DISCLOSUREThis application is a continuation of application No. 785,045, filedDec. 12, 1968, now abandoned, which in turn is a continuation ofapplication No. 517,225, filed Dec. 29, 1965, now abandoned.

This invention relates to a method of forming an integrated mass from acollection of linear bodies generally, and more particularly to a methoduseable in the formation of fibrous masses or products whereinsuccessively arranged stations deliver fibrous or filamentary materialsonto a moving collector to produce an assemblage or product.

In the manufacture of fibrous products such as fibrous mats, it is apractice to employ several fiber or filament forming and processingstations or units arranged to concomitantly and continuously depositattenuated filaments or fibers on a moving conveyor belt or collector toform a built-up fibrous mass or mat as a composite of the filaments orfibers from the several stations or units. In such methods or processesit is essential, in order to produce a uniform product to maintain,insofar as possible, the continuous operation of the several fiber orfilament forming and depositing units. Great strides have been made inmechanical and process approaches for attaining the uniformity ofdeposition of the product and thus the uniformity of the fiber contentof the mat. However, it is also normally desirable to integrate thecontinuous strands in mat form through the application of a suitablebinder. Difficulties have been encountered in prior methods of ap plyingthe binder in attaining a uniform deposition and dispersion of thebinder throughout the mat or fibrous product. Variations resulting fromthe use of prior art processes have resulted in weight and densitydifferences across the width and along the length of the mat, sometimesrequiring additional processing of the mat before its use in the endproduct. In the past, liquid binders have been sprayed upon the mat asit has been formed, the binder usually consisting of a resin type ofbinder carried in an aqueous solution or suspension. In another methodpowdered binder has been sifted onto the mat shortly after formation andthe water or liquid lubricant on the strands is relied upon to adherethe powdered binder to the strands.

In both of the prior art methods, the mat is then moved along a conveyorinto a treating area which may comprise an oven for drying and curingthe hinder or a means for applying accelerator or other chemical curingmethods to the binder, whether in liquid form, fumes, etc.

As more sophisticated uses have developed for the in- Patented Aug. 1,1972 tegrated fibrous mats and similar products, the distribution of thebinder within the interior of the mat has become increasingly important.The distribution may, for example, change the molding characteristics ofthe mat whenever it is utilized in making a reinforced product. Further,the exact amount of binder in the mat has become more important forcertain applications and it is evident that the prior art methods caninsure neither the distribution nor the amount in weight or volume ofbinder in a mat with the degree of certainty required.

Accordingly, it is an object of this invention to provided an improvedmethod and means for forming an integrated mass from a collection oflinear bodies.

It is a further object of this invention to provide an improved methodand means for applying a binder to a fibrous mat.

It is still a further object of this invention to provide an improvedmethod and means for controlling within very close tolerances thedistribution and/or the quantity of a binder in weight or volume that isto be applied in a mat of fibrous materials to integrate the linearbodies into mat form.

A still further object of this invention is to provide a method andmeans for forming fully loaded sheets of fibrous material with an exactamount of the various reactants and binders required therein which maybe immediately used after the forming step in the making of the' finalproduct without requiring intermediate steps to in sure that the fullpercentage of binder and filler that is required is present.

Yet another object of this invention is to provide an improved methodand means of integrating continuous or discontinuous strands in mat formthrough the application of a suitable binder without encountering theblocking, clogging, etc., on the forming chains or belt of thecollecting conveyor that is associated with the application of wet orpowdered type binders.

The invention features a method of forming an integrated mass from acollection of linear bodies which comprises the steps of providing alayer of said bodies, overlaying the layer with binder in film form, andactivating the film to disperse the binder among the individual bodiesto bind them into an integrated mass. The method may, of course, beextended to providing a plurality of layers of individual linear bodiesand interleafing binder in film form between the layers. The activatingstep may include exposing the film to a predetermined chemical catalystor accelerator. In addition to the use of an accelerator or as analternative thereto, the activating step may include exposing the filmto a heat treatment. The heat treatment may include melting and flowingthe film to bond abutting individual bodies. In the case of the smallerstrands discussed herein, the film may be melted and flowed around theintersections of the bodies and then solidified and shrunk around theintersections. In addition to the steps above that are commonly usedwith thermoplastic hinders the activating step for a thermosettingbinder may include heating the film to shrink and separate the film intodiscontinuous segments and curling the segments around the bodies tomechanically integrate the mass. Obviously the thermoplastic andthermosetting binders in film form may be combined, either in separatesheets or in the same sheet to provide the melting and flowing andbonding of intersections as well as the mechanical integrating action ofthe curling of thermosetting segments around the linear bodies. By usingthe method of this invention a sufficient amount of binder in film formmay be interleafed in the layers of individual bodies to enable the useof the combined layers and interleafing film in a final molding processwithout intermediate steps to insure that a suflicient percentage ofbinder is present.

In the inventive method disclosed herein the steps of providing aplurality of layers of individual linear bodies may include the steps offorming linear bodies of heat softened material, such as glass, fromsupplies at a plurality of body forming and delivery stations,continuously delivery a group of linear bodies from each of the stationsto a collecting zone where the bodies are collected into an assemblage,and continuously moving the assembladge of bodies away from thecollecting zone thereby forming a layer. When the pluarality of formingand delivery stations are utilized, the interleafing step mayadvantageously be accomplished by providing supplies of binder in filmform intermediate the forming and delivery stations, dispensing film ontop of a layer from a preceding station, and collecting a layer oflinear bodies from a succeeding forming station on top of the dispensedfilm.

The invention also features novel apparatus for carrying out the methodsof this invention.

Other objects, advantages and features of this invention will becomeapparent when the following description is taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a schematic side elevational view illustrating an apparatusfor carrying out the method of this invention by the use of a pluralityof fiber or filament attenuating stations or units:

FIG. 2 is a view in perspective of a film roll suitable for use in theapparatus of FIG. 1;

FIG. 3 is a view in perspective of a diiferent application of film inthe apparatus of FIG. 1; and

FIG. 4 is an illustration of a variation of the film that may beutilized in the method of this invention.

While the invention is illustrated in association with apparatus forattenuating heat-softened material, such as glass, to filaments orfibers which are distributed onto a moving conveyor, it is to beunderstood that the invention may be utilized in many other mat makingor mass integrating processes wherein an even distribution, control ofquantity, or other very accurate integrating requirements are specified.

In the arrangement illustrated in the drawings, the attenuatingapparatus is particularly usable for attenuating streams ofheat-softened glass or other heat-softened material to continuousfilaments converged into strands and the strands from the several unitsdistributed onto a moving conveyor to form a collective mass or mat ofthe continuous filaments.

As noted above, the invention does not have to be used with thecontinuous line nor with a continuous mat making process. Even if theinvention is to be used with a continuous line, it may also be used witha chopped strand, spinner or centrifugal drawing of fibers, or otherprocesses to build up depth of mat on a continuously moving conveyor.

Referring to FIG. 1 there is illustrated an apparatus for attenuatinggroups of streams of glass into continuous filaments which are convertedinto strands which are collected to form an assemblage or fibrous mass.A plurality of stream feeders are arranged in two spaced parallel rows,each adapted to contain a supply of heat-softened materials such asheat-softened glass. The feeders 10 may be directly connected with aforehearth of a melting furnace to receive glass therefrom, or pieces orspherical bodies of glass may be delivered into the feeders and melteddirectly therein.

Each of the feeders 10 is provided at its ends with terminals 12connected with an electric current of high amperage and low voltage formaintaining the softened glass at a proper viscosity for attenuation orfor melting and conditioning material Where the latter is introducedinto the feeders in pieces or spherical bodies. Each of the streamfeeders is provided with a plurality of orifices in the bottom or floorthrough which flow groups of streams adapted to be attenuated tocontinuous filaments 16 by rotating attenuating instrumentalities.

As illustrated, the group of filaments formed from the streams from eachfeeder is converged by a suitable gathering shoe 18 into amulti-filament strand 20, each group of filaments forming a strand.

It is desirable to applied a liquid, such as'water, onto the filamentsprior to their convergence into strand form for lubrication and otherpurposes. Disposed above each of the gathering shoes 18 is a receptacle22 adapted to contain water or other liquid applied to a fan or group offilaments by belt-like applicator 24 which, moving through the liquid inthe receptacle, acquires a film thereof which is transferred to thefilaments by a Wiping contact.

A fiber or filament attenuating and distributing unit 26 is disposedbeneath or adjacent each of the stream feeders 10 for attenuating thefilaments of each group by mechanical means. Each attenuating unit isinclusive of a rotatable strand-engaging means or pull wheel 30journally mounted upon a support which in turn is mounted on a frameconstruction 34. The pull wheel 30 is mounted on a shaft 36 on which issecured a sprocket driven by a belt from a second sprocket mounted on ashaft of an electrically energizable motor 42. Journally supported onmeans 45 carried by the frame member 34 are idler rolls 44. A pull wheelor attenuating unit and at least one idler roll is provided for eachstrand 20.

The strand 20 passes around the idler roll 44 and around the attenuatingor pull wheel 30 and is delivered or project from the pull wheel fordistribution on a relatively movable collector or conveyor belt 50. Eachof the attenuating units 26 embodies means for disengaging the strandfrom the pull Wheel 30 at varying peripheral regions of a pull wheel toelfect transverse or lateral distribution of the strand over the widthof the collector or conveyor 50. As the conveyor is advanced past theseveral fiber attenuating stations or units, the several strands aresuccessively overlapped in building up a mat of desired thickness. Thewater or other liquid delivered onto the filaments by the applicatorsprovides adequate wetting or lubricating of the filaments withoutincurring an excess of liquid in the mass or mat of the accumulatedstrands on a conveyor 50.

The apparatus just shown thus is capable of performing steps ofproviding a layer or a plurality of layers of individual linear bodiesby forming the linear bodies of heat-softened material from the suppliesat the plurality of body forming and delivery stations, continuouslydelivering a group of linear bodies from each of the stations to acollecting zone where the bodies are collected into an assemblage, andcontinuously moving the assemblage of bodies away from the collectingzone.

In order to accomplish the interleafing step of the method, supplies ofbinder in film form are provided intermediate the forming and deliverystations. Rolls of binder 60 in film form are carried on a dispensingshaft 61 located above the conveyor and intermediate the formingstations. If necessary, a guide roller 62 may be placed just above thepreviously formed layer to assist in the disposition of the binder filmon top of a previously formed layer without interfering with thedeposition as a successively formed layer on top of the film beingdispensed. The shaft 61 may be mechanically tied to the drive means ofthe conveyor to insure that the film is dispensed at a speedsubstantially equal to the conveyor speed. In order to insure an exactdeposition speed according to a predetermined conveyor speed, a rubberor other yieldably engageable roller type means 70 may be placeddirectly on the surface of the roll insuring that the circumference ofthe roll travels at the same speed as the conveyor even though thediameter of the roll becomes successively smaller as each wrap is takentherefrom. In such a driving means the shaft 61 would be journaled toroll freely and the driving means geared to the speed of the conveyor.The roller or shaft 62 may, of course, be directly driven by theconveyor since its circumference does not change or vary, or it may beallowed to rotate freely.

Referring to FIG. 2 there is illustrated in perspective a roll 60 of thebinder in film form mounted on the shaft 61. The material used in thebinder film may vary according to the applications in which theintegrated mat will be utilized after integration. For example,thermoplastic binders may be made up in film form such as the resinvinyls, polyesters, polyethers, etc. This type of film may be activatedthrough a heat treatment which will cause the film to melt and flow onthe fibers themselves, particularly at the intersections thereof, andwhich will solidify and shrink around the intersections after the heattreatment to integrate the mass together. Thermosetting binder films maybe used which may be activated by external temperatures but moreprobably by the use of accelerators in combination with externallyapplied temperatures, which accelerators may be applied in liquid spray,fumes or other forms so that the integrated mass may be molded or curedquickly and then put into an oven for the final setting or curing.

Combinations of thermoplastic and thermosetting binders in film form maybe utilized in which the thermoplastic may be activated at a firstpredetermined time, usually by the application of heat, while thethermosetting film binder may be activated at a second perdeterminedtime, usually in conjunction with the accel erators or catalystsdiscussed hereinbefore. The thermoplastic and thermosetting binders maybe combined intoa single sheet or film form, or the film dispensingstation intermediate the forming stations may include two or more rollsof film for inclusion between the layers of linear bodies to accomplishthe results as desired at a later time. In this connection it may benoted that fully loaded sheets may be formed from this process in whicheverything is in the combined layers of linear bodies and interleafedfilms of binder so that the combined layers and interleafing may be useddirectly in the final process with the full percentage of fiber andbinder needed, without intermediate stages or treatment to insure thatthe percentage and/or distribution is correct.

It is obvious that by using various thicknesses of film binder and byinterleafing the film as desired between suitably thickened layers offibers, that binder may be applied to integrate the mass in a most exactquantity in weight or volume and that the distribution of the binderwill be uniform.

As noted in FIGS. 3 and 4, the binder in film form need not be appliedas a sheet of film. For example, in FIG. 3 strips of binder film may beunrolled from a previous binder dispensing station, which strips 60awill be intersticed with, although a layer below, similar strips 60b ata succeeding film dispensing station. Thus the film may be interleafedin staggered layers and three dimensional matrices to accomplish theresult desired. Further, the strips 60a may be of a thermoplastic natureto achieve a first result, while the strips 60b may be of athermosetting or other nature, to be described hereinafter, toaccomplish a separate result. The three dimensional matrix formed by theuse of the strips shown herein does allow an air circulation up throughthe mat, particularly a heated air circulation, when it would bedesirable to activate the thermoplastic binder. When combining one ormore types of binders in full sheet form as shown by the sheet 60 inFIG. 2, air circulation through the mat would be difficult.Alternatively, there is shown in FIG. 4 a sheet 600 which has formedtherein perforations 65 which would permit air circulation through themat for drying or curing purposes while still retaining substantiallythe uniformity of distribution and density of the binder in the mat whenfinally integrated.

It is to be noted that the mat may also be integrated by using filmswhich include a cellulose acetate, viscose yarn, etc., which do notmelt, but instead curl and shrink in response to a heat treatment. Thecurling and shrinking action performs a mechanical locking or bonding ofthe fibers into an integrated mat. The films of this nature may beprovided in the solid sheet type shown in 60 which, upon application ofheat, will tack or separate and shrink and split into discontinuoussegments, which segments will curl and shrink further and perform themechanical locking and integrating action described above. As analternative discontinuous threads of the curling and shrinking naturemay be placed in a carrier film of a thermoplastic base to provide adouble action. Such threads, yarns or discontinuous segments may be alsoutilized in a carrier film which will disintegrate after heat or othertreatment and not stay in the mat, leaving only the discontinuousthreads or segments so that only mechanical locking is accomplished.This would be of particular importance in special applications such as,for example, filter mats in which it is desirable to provide as muchfiber surface as possible to filter air or gases being driventherethrough. The fiber surfaces in this instance are more capable ofcollecting the dust or dirt from air, other gases, or liquids beingdriven through the filter than certain binders, which may be utilized tointegrate the mass and of necessity cover a portion of the fibrous dirtcollecting surfaces.

Referring again to FIG. 1 there is illustrated means for activating thebinder film to integrate the fibrous mass.

If a heat treatment is desired an oven 70 may be utilized. Heat may beprovided by a radiant type heating means 71 and or by blower means 72circulating air or other gases past heating elements 73. Both heatingmethods may be controlled by a thermostat means 74 connected to asuitable temperature control means 75. If desired the heated air orgases may be recriculated in a closed system via an exhaust port 76connected to blower 72.

Depending upon whether the binder film is thermoplastic or thermosettingor a combination of both a chemical accelerator or catalyst may beapplied. As shown in FIG. 1 the accelerator is being applied by nozzle80 in liquid spray form although prior art methods of using fumeapplications, etc., may be used.

To indicate that fully loaded sheets may be assembled by this processfor immediate use, a compression roller is shown in FIG. 1 to note thatcompression or molding may be initiated directly. Obviously a series ofcompression rollers, mating compression platens, or mating molds may beused.

In the method described herein the shelf life of a binder film,particularly that of the mechanical locking nature would be much longerthan the aqueous solutions which must be continuously agitated to keepits capabilities or the powdered forms of binder which may cake orotherwise become aged. Further, the collecting conveyor, such as theconveyor 50 illustrated in FIG. 1 moving beneath the forming stations,would have little or no tendency to become clogged or blocked with theuse of the film binder as illustrated as opposed to the previous use ofbinder in an aqueous solution or the distribution of powdered binder ona wetted mass. Thus the expense of storage, the stocking requirements,the labor and equipment involved, are all smaller with the use of themethod disclosed herein. The method enables insuring an exact amount ofbinder distributed in any desired fashion within very close toleranceson weight or volume when integrating a mat or mass and when providingfully loaded sheets for final processing.

It is apparent that, within the scope of the invention, modificationsand different arrangements may be made other than as herein disclosed,and the present disclosure is illustrative merely, the inventioncomprehending all variations thereof.

I claim:

1. The method of accurately and uniformly dispersing a metered amount ofbinder throughout the interior of a mass of loose glass fibers to form asingle integrated mat-like collection of individually interconnectedloose fibers having a uniform density, comprising the steps ofdepositing a plurality of layers of loose glass fibers, metering anduniformly distributing predetermined amounts of binder by interleafingbinder in film form between said layers of loose fibers, and dispersingsaid binder in film form through said layers of loose fibers tointerconnect adjoining portions only of said loose fibers Within andbetween said layers to form an integrated collection of individual glassfiber bodies.

2. The method according to claim 1 in which said dispersing stepincludes heating said film.

3. The method according to claim 1 in which said dispersing stepincludes the application of sufficient heat to melt and flow said film.

8 4. The method according to claim 1 in which said dispersing stepincludes changing the temperature of said film to separate the film intodiscontinuous segments and cause the segments to curl around adjacentfibers to mechanically interconnect said loose fibers.

References Cited UNITED STATES PATENTS 2,543,101 2/1951 Francis, Jr.156-622 2,523,022 9/1950 Horstman l61143 FOREIGN PATENTS 621,867 4/1949Great Britain 15662.2

BENJAMIN A. BORCHELT, Primary Examiner H. J. TUDOR, Assistant ExaminerUS. Cl. X.R.

